When an electric device is in a standby state or the like, there is a case where the electric device disconnects the device itself or a memory system in a memory card from a power supply in order to suppress consumption power of the device. In this case, when the electric device returns from the standby state to a startup state, the memory system is connected to the power supply, and reads out an operating parameter from a nonvolatile memory to a volatile memory (hereinafter, also “cache”). The operating parameter is basic information for defining operating conditions such as a word line voltage and a bit line voltage in a read operation, a write operation, or an erase operation in a memory chip. The operating parameter is stored in advance in the nonvolatile memory in the memory system, and is read out to a volatile cache (a register) in the memory chip so that a high-speed access can be made when the power is turned on. This read operation of the operating parameter is called POR (Power On Read). When the memory system is operated, the memory chip is operated according to the operating parameter stored in the cache.
However, when turning on and turning off of the power of the memory system or the memory chip are repeated, the number of times of POR is increased, and thus read disturb is caused on the nonvolatile memory having an operating parameter stored therein. When a wrong operating parameter is read out to the cache due to the read disturb, the memory system cannot be operated normally.
To handle such a problem, there is a case where the same operating parameters are stored in a plurality of positions of a nonvolatile memory. When an operating parameter of a certain position is broken, the memory system reads out an operating parameter stored in another position. However, in this case, when many operating parameters are broken, the memory system needs to access many positions in the nonvolatile memory for many times, causing a problem that a long time is taken to read out the operating parameter to the cache.